8 red flashes Flame lost repeatedly (recycles)

What the control is telling you

The flame dropped out too many times in one call (five losses / four recycles on the TM9V). One-hour soft lockout.

Applies to: York/JCI residential gas furnaces: York UTEC IFC furnaces, York White-Rodgers IFC furnaces, York TM9V

Likely causes

• Low gas pressure
• Dirty or faulty flame sensor
• Faulty gas valve
• Poor ground

Test and repair steps

1. Check inlet and manifold pressure during the run.
2. Clean the flame sensor and check flame current.
3. Check the burner ground.
4. Replace the gas valve if it drops out with good pressure and signal.
5. To read stored codes with no thermostat call active, tap the LAST ERROR button briefly (under 5 s); up to five codes play back newest first. Two green flashes = memory empty. Hold the button 5 s or more to clear (three green flashes confirm).

Settings for these units

Clearance to combustibles · York TM9V

Leave about 24 in. at the front and 18 in. at the side for service.

Approved for alcove and attic installs.

Filter size by return location · York TM9V

Sizes assume high velocity filters (600 FPM); throwaway filters must stay at or below 300 FPM.

Filters go outside the cabinet - never inside the furnace.

Models that show this code

7 models in York UTEC IFC furnaces, York White-Rodgers IFC furnaces, York TM9V

Other codes on the same units

• 4 red flashes Main limit switch open
• 5 red flashes Rollout switch open / limit circuit open over 15 min
• 6 red flashes Pressure switch cycling lockout
• 7 red flashes Ignition failure lockout (retries)
• 9 red flashes Polarity reversed or bad ground
• 10 red flashes Gas valve powered with no heat call
• 11 red flashes Limit open 5-15 minutes - blower failure
• 12 red flashes Hot surface igniter open / igniter failure